Caroline and Maria may be glamour girls but they're working their way to the very top

It is widely supposed that women's tennis has been in a slump in the past few years, struggling to emerge from the shadow of a men's game with compelling rivalries that has been enjoying a perceived golden era.

APPEARANCE DOESN'T MATTER

Forbes, the American bible of all matters wealth-related, would appear to disagree with the first part of that. In its most recent totting up of the world’s richest female athletes, tennis players occupied seven of the top 10 places.

Perhaps that is related to the mild rebuke issued this week by Britain’s former Wimbledon champion Ann Jones, who wondered if today’s stars do not spend too much time focusing on fame, glamour and earning opportunities away from the court.

Powerful: Caroline Wozniacki is among the world's leading talents

‘Part of me says they should get on with the game. I know my parents would have said that to me,’ mused the 1969 winner at SW19, who also conceded that having attractive players on the WTA Tour might not be a bad thing either.

One of her comments pertained directly to Caroline Wozniacki, the former world No 1 who happens to be Rory McIlroy’s girlfriend and recently launched her own line of underwear.

Referring to the Dane’s fruitless attempts to win a Grand Slam, the eminently sensible former Sports Personality of the Year posed: ‘Maybe she accepts that she can’t and wants fame in a different direction.’

Rival: Maria Sharapova is another at the top of the game

This kind of question often surrounds Wozniacki, who has twice been the year-end No 1 without having won a major. And it is true that her No 4 position in the Forbes top 10 makes her something of an overachiever financially, as she currently ranks No 10 in the world.

But is the cheerful 22-year-old — along with her peer group of fabulously wealthy players — the modern day equivalent of an Anna Kournikova, who became the prime example of a player whose celebrity and earning power outstripped her achievements on court?

Wozniacki has certainly done well out of endorsing the likes of adidas apparel, Proactiv skin care and now her own lingerie line, but from a pure tennis point of view she could also be described as an over-achiever.

Glamour: Both are also accustomed to the high life outside of tennis

Her game does not have the weaponry that most of her rivals enjoy, relying more on physical durability, good movement and working points from the baseline. While the blossoming relationship with the golfer was undoubtedly a distraction at first, hers is not the kind of game style that can work without plentiful dedication.

Nor is that of the mother of all female athlete-earners, Maria Sharapova, reckoned to have brought in £17.8million last year. She is a hive of commercial activity and while her latest venture, promoting sweets called Sugarpova, is certainly dubious for a role model athlete, the blonde Russian shows no sign of slacking on the court, having had her best 12 months since 2006.

Experienced view: Ann Jones was also a quality player during her heyday

Her earnings have even been enough to see off No 2 in the Forbes list Li Na, whose 2011 French Open title sparked a China-led sponsor frenzy that led to her signing seven deals believed to be worth around £26.4m over three years.

If anyone could have been accused in recent times of neglecting their sport for off-court pursuits it would be Serena Williams, who for several seasons seemed to treat the tour as an optional extra to her outside activities such as appearing on shopping channels, getting by on enormous talent alone. Yet even she has re-dedicated herself in the past 12 months and the results proved it.

The list of overall earners roughly corresponds to the official top 20, still a competitive roster in a global sport which is based on results of the previous year, so there are few shortcuts to riches.

There is further good reason for the top women not to take their eye off the ball with excessive distractions: the fact that they have never had it so good in terms of actual prize money, which dwarfs other athletic pursuits.

Celebrity couple: Wozniacki is in a relationship with one of the world's leading golfers, Rory McIlroy

This is down to two factors. Firstly, having secured equal purses at the Grand Slams the women have quietly piggy-backed the men’s campaign for a greater share of tournament revenues, and despite being less of a draw (at least right now) get half the massive increases seen at the Australian Open and US Open this year.

Also, they have skilfully moved into emerging markets such as China, Turkey and the Middle East, where tournaments are often backed by governments eager to gain international exposure.

And the fact is that early rounds remain statistically less taxing for the top women. For instance in Melbourne this year 28 of 64 first round matches were won for six games or less, also allowing time for some to make extra cash in the doubles.